<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<button id="btn_1" onclick="fun1()">点我</button>
<input type="submit" onclick="fun1()">
<input type="button" id="double" value="双击" >

<script type="text/javascript">
    function fun1() {
        alert("你点了")
    }

    var doubleInput=document.getElementById('double');
    doubleInput.ondblclick=function () {
        alert(666)
    }
</script>

</body>
</html>